IEC 62790:2020
(Main)Junction boxes for photovoltaic modules - Safety requirements and tests
Junction boxes for photovoltaic modules - Safety requirements and tests
IEC 62790:2020 is available as IEC 62790:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62790:2020 describes safety requirements, constructional requirements and tests for junction boxes up to 1 500 V DC for use on photovoltaic modules in accordance with class II of IEC 61140:2016.
This document applies also to enclosures mounted on PV-modules containing electronic circuits for converting, controlling, monitoring or similar operations. Additional requirements concerning the relevant operations are applied under consideration of the environmental conditions of the PV-modules. This document does not apply to the electronic circuits of these devices, for which other IEC standards apply. This second edition cancels and replaces the first edition published in 2014. This edition includes the following significant technical changes with respect to the previous edition:
- Modifications in normative references and terms and definitions;
- Improvement of declaration of categories for junction boxes in 4.1;
- Clarification for ambient temperature in 4.1;
- Addition of requirement to provide information concerning RTE/RTI or TI in 4.2;
- Reference to IEC 62930 instead of EN 50618 in 4.6;
- Addition of "Functional insulation" in Table 1;
- Addition of "Distance through cemented joints" in Table 3;
- Correction of procedure of process to categorize material groups (deletion of PTI) in 4.15.2.3;
- Requirement for approval of RTE/RTI or TI for insulation parts in 4.16.1 and 4.16.2;
- Change of requirements concerning electrochemical potential in 4.17.2;
- Clarification for IP-test in 5.3.4.2;
- Addition of test voltage for cemented joints in 5.3.6 and 5.3.16;
- Addition of detailled description on how to prepare the test sample for the thermal cycle test in 5.3.9.1;
- New test procedure for bypass diode thermal test (5.3.18) in accordance with MQT 18.1 of IEC 61215-2:2016;
- New test procedure for reverse overload current test in 5.3.23;
- New Figure 1 for thermal cycle test.
Boîtes de jonction pour modules photovoltaïques - Exigences de sécurité et essais
IEC 62790:2020 est disponible sous forme de IEC 62790:2020 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.
L’IEC 62790:2020 décrit les exigences de sécurité, les exigences de construction et les essais relatifs aux boîtes de jonction jusqu’à 1 500 V en courant continu utilisées sur des modules photovoltaïques conformes à la classe II de l’IEC 61140:2016. Le présent document s’applique également aux enveloppes montées sur des modules photovoltaïques comportant des circuits électroniques pour la conversion, le contrôle, la surveillance ou opérations similaires. Des exigences supplémentaires concernant les opérations correspondantes sont appliquées en considérant les conditions d’environnement des modules photovoltaïques. Le présent document ne s’applique pas aux circuits électroniques de ces dispositifs pour lesquels d’autres normes IEC s’appliquent. Cette deuxième édition annule et remplace la première édition parue en 2014. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- Modifications des références normatives et des termes et définitions;
- Amélioration de la catégorisation des boîtes de jonction en 4.1;
- Clarification de la température ambiante en 4.1;
- Ajout de l'exigence prévoyant de fournir les indices RTE/RTI ou IT en 4.2;
- Référence à l’IEC 62930 à la place de la référence à l’EN 50618 en 4.6;
- Ajout de "l'isolation fonctionnelle" dans le Tableau 1;
- Ajout de "ligne de fuite entre les bords du joint scellé" dans le Tableau 3;
- Correction de la procédure du processus de catégorisation des groupes de matériaux (suppression de l’ITC) au 4.15.2.3;
- Exigence d'approbation des indices RTE/RTI ou IT pour les parties isolantes en 4.16.1 et 4.16.2;
- Modification des exigences concernant le potentiel électrochimique en 4.17.2;
- Clarification des essais de vérification du code IP au 5.3.4.2;
- Ajout de la tension d'essai pour les joints scellés en 5.3.6 et 5.3.16;
- Ajout de la description détaillée sur la façon de préparer les éprouvettes pour l'essai de cycle thermique en 5.3.9.1;
- Nouvelle procédure d'essai pour l'essai thermique la diode de dérivation (5.3.18) conformément au MQT 18.1 de l’IEC 61215-2: 2016;
- Nouvelle procédure d'essai pour l'essai de courant de surcharge inverse au 5.3.23;
- Nouvelle Figure 1 pour l'essai de cycle thermique.
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IEC 62790 ®
Edition 2.0 2020-07
REDLINE VERSION
INTERNATIONAL
STANDARD
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Junction boxes for photovoltaic modules – Safety requirements and tests
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The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
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IEC 62790 ®
Edition 2.0 2020-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Junction boxes for photovoltaic modules – Safety requirements and tests
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-8680-7
– 2 – IEC 62790:2020 RLV © IEC 2020
CONTENTS
FOREWORD . 5
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 11
4 Constructional requirements and performance . 15
4.1 General . 15
4.2 Marking and identification . 16
4.2.1 Identification . 16
4.2.2 Marking . 16
4.2.3 Technical documentation . 16
4.3 Protection against electric shock . 17
4.4 Terminations, connecting devices and connection methods . 17
4.5 Connectors . 18
4.6 Cables . 18
4.7 Resistance to ageing . 18
4.8 General design . 18
4.9 Degree of protection (IP) . 19
4.10 Dielectric strength . 19
4.11 Range of ambient temperature . 19
4.12 Cable anchorage . 19
4.13 Mechanical strength . 19
4.14 Insulation . 20
4.14.1 Type of insulation . 20
4.14.2 Basic insulation . 20
4.14.3 Supplementary insulation . 20
4.14.4 Double insulation . 20
4.14.5 Reinforced insulation . 20
4.15 Clearances and creepage distances . 20
4.15.1 Clearances . 20
4.15.2 Creepage distances . 21
4.16 Insulation parts . 23
4.16.1 Outer accessible parts . 23
4.16.2 Inner parts keeping active parts in position . 23
4.17 Current carrying parts and resistance against corrosion . 24
4.18 Sealing . 24
4.19 Bypass-diode . 24
4.20 Knock-out inlets (outlets) intended to be removed by mechanical impact . 24
5 Tests . 24
5.1 General . 24
5.2 Preparation of specimens . 26
5.3 Performance of tests . 27
5.3.1 General . 27
5.3.2 Durability of marking . 27
5.3.3 Fixing of lid on rewirable junction box . 27
5.3.4 Protection against electric shock . 28
5.3.5 Measurement of clearances and creepage distances . 28
5.3.6 Dielectric strength . 28
5.3.7 Resistance to corrosion . 28
5.3.8 Mechanical strength at lower temperatures . 29
5.3.9 Thermal cycle test (IEC 60068-2-14:2009, Test Nb) . 29
5.3.10 Damp heat test . 30
5.3.11 Weather resistance test . 30
5.3.12 Flammability class . 30
5.3.13 Ball pressure test . 31
5.3.14 Glow wire test . 31
5.3.15 Resistance against ageing . 31
5.3.16 Wet leakage current test . 31
5.3.17 Humidity freeze test . 32
5.3.18 Bypass diode thermal test . 33
5.3.19 Test of terminations and connection methods . 34
5.3.20 Knock-out inlets (outlets) intended to be removed by mechanical impact . 34
5.3.21 Test of cord anchorage . 35
5.3.22 Retention on the mounting surface . 37
5.3.23 Reverse current test at junction box . 37
5.4 Test schedule . 38
Annex A (informative) Symbol "Do not disconnect under load" . 50
Annex B (normative) Qualification of conformal coatings for protection against
pollution . 51
B.1 General . 51
B.2 Technical properties . 51
B.3 Qualification of coatings . 51
Annex C (normative) Measurement of clearances and creepage distances . 54
Bibliography . 58
Figure 1 – Thermal cycling test – Temperature and applied current profile . 45
Figure 2 – Humidity-freeze cycle . 45
Figure 3 – Typical arrangement for the cable anchorage pull test . 46
Figure 4 – Typical arrangement for torsion test . 46
Figure 5 – Typical arrangement for flammability test in accordance with 5.3.12.2 . 47
Figure 6 – Measurement of voltage drop . 47
Figure 7 – Bypass diode thermal test . 48
Figure 8 – Proper attachment of 5 N weight to junction box. 49
Figure A.1 – Symbol "DO NOT DISCONNECT UNDER LOAD" . 50
Figure A.2 – Symbol "DO NOT DISCONNECT UNDER LOAD" (IEC 60417-6070:2011-06) . 50
Figure C.1 – Examples of methods of measuring clearances and creepage distances . 57
Table 1 – Required type of insulation . 20
Table 2 – Rated impulse voltages and minimum clearances . 21
Table 3 – Creepage distances for basic insulation . 22
Table 4 – Number of specimens . 25
Table 5 – Values of torque for screw-type clamping units . 26
Table 6 – Pull forces for cord anchorage . 36
– 4 – IEC 62790:2020 RLV © IEC 2020
Table 7 – Values for torsion test . 36
Table 8 – Marking, information, documentation, test group A . 38
Table 9 – Material test, test group B (single tests) . 39
Table 10 – Constructional requirements, test group C (single tests) . 40
Table 11 – Mechanical tests, test group D (single tests) . 40
Table 12 – Test sequence I, test group E (tests to be performed consecutively in this
order).
...
IEC 62790 ®
Edition 2.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Junction boxes for photovoltaic modules – Safety requirements and tests
Boîtes de jonction pour modules photovoltaïques – Exigences de sécurité
et essais
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
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Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
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once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.
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IEC 62790 ®
Edition 2.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Junction boxes for photovoltaic modules – Safety requirements and tests
Boîtes de jonction pour modules photovoltaïques – Exigences de sécurité
et essais
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.160 ISBN 978-2-8322-8488-9
– 2 – IEC 62790:2020 © IEC 2020
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 9
4 Constructional requirements and performance . 13
4.1 General . 13
4.2 Marking and identification . 14
4.2.1 Identification . 14
4.2.2 Marking . 14
4.2.3 Technical documentation . 15
4.3 Protection against electric shock . 15
4.4 Terminations, connecting devices and connection methods . 15
4.5 Connectors . 16
4.6 Cables . 16
4.7 Resistance to ageing . 16
4.8 General design . 16
4.9 Degree of protection (IP) . 17
4.10 Dielectric strength . 17
4.11 Range of ambient temperature . 17
4.12 Cable anchorage . 17
4.13 Mechanical strength . 17
4.14 Insulation . 18
4.14.1 Type of insulation . 18
4.14.2 Basic insulation . 18
4.14.3 Supplementary insulation . 18
4.14.4 Double insulation . 18
4.14.5 Reinforced insulation . 18
4.15 Clearances and creepage distances . 19
4.15.1 Clearances . 19
4.15.2 Creepage distances . 19
4.16 Insulation parts . 21
4.16.1 Outer accessible parts . 21
4.16.2 Inner parts keeping active parts in position . 21
4.17 Current carrying parts and resistance against corrosion . 21
4.18 Sealing . 22
4.19 Bypass-diode . 22
4.20 Knock-out inlets (outlets) intended to be removed by mechanical impact . 22
5 Tests . 22
5.1 General . 22
5.2 Preparation of specimens . 23
5.3 Performance of tests . 25
5.3.1 General . 25
5.3.2 Durability of marking . 25
5.3.3 Fixing of lid on rewirable junction box . 25
5.3.4 Protection against electric shock . 25
5.3.5 Measurement of clearances and creepage distances . 26
5.3.6 Dielectric strength . 26
5.3.7 Resistance to corrosion . 26
5.3.8 Mechanical strength at lower temperatures . 26
5.3.9 Thermal cycle test (IEC 60068-2-14:2009, Test Nb) . 27
5.3.10 Damp heat test . 28
5.3.11 Weather resistance test . 28
5.3.12 Flammability class . 28
5.3.13 Ball pressure test . 29
5.3.14 Glow wire test . 29
5.3.15 Resistance against ageing . 29
5.3.16 Wet leakage current test . 29
5.3.17 Humidity freeze test . 30
5.3.18 Bypass diode thermal test . 30
5.3.19 Test of terminations and connection methods . 31
5.3.20 Knock-out inlets (outlets) intended to be removed by mechanical impact . 32
5.3.21 Test of cord anchorage . 32
5.3.22 Retention on the mounting surface . 34
5.3.23 Reverse current test at junction box . 34
5.4 Test schedule . 35
Annex A (informative) Symbol "Do not disconnect under load" . 45
Annex B (normative) Qualification of conformal coatings for protection against
pollution . 46
B.1 General . 46
B.2 Technical properties . 46
B.3 Qualification of coatings . 46
Annex C (normative) Measurement of clearances and creepage distances . 49
Bibliography . 53
Figure 1 – Thermal cycling test – Temperature and applied cur
...
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